Aligning means for belt conveyers



July 24, 1951 gmm 2,561,641

ALIGNING MEANS FOR BELT GONVEYERS Filed May 6, 1947 2 Sheets-$heet lIIIIII II V, ////l/1lI,/ \I

FIG 31.

[NV-[W703 t/g/ms' 77/0/750/1 WWW July 24, 1951 J. THOMSON 2,561,641

ALIGNING MEANS FOR BELT CONVEYERS Filed May 6, 1947 2 Sheets-Sheet 2Patented July 24, 1951 FFICE ALIGNING MEANS FOR BELT CONVEYERS I JamesThomson, Glasgow, Scotland, assignor to Mavor & Coulson, Limited,Glasgow, Scotland l Application May 6, 1947, Serial No. 746,375

' In Great Britain April 16, 1945 6 Claims. (Cl. 198-202) r Thisinvention refers to conveyors of the endless belt type, in which atleast one run of the belt is carried by a series of idler rollersincorporated in training, or self-aligningunits supported by swivelmountings.

The invention is especially, although not ex- .c'lusively, applicable.to conveyors of the type stated in which the conveying run of the beltis troughed transversely by the use .of inclined idler rollers on whichthe belt is .carried. A usual arrangement is for-the idler rollers to begrouped in sets of three rollers, each set comprising a horizontalcentralroller and an inclined outer roller at each side end-to-end withthe central roller. There may of course be other numbers of rollers in aset to give the desired. trough effect. The main objector this inventionis to provide an improved construction of belt-correcting means, thepurpose of which is to return the belt to centralised running in theevent that it should deviate to one or otherside and which acts, in caseof need, in -two belt-correction stages, namely-a first stage action inwhich a minor corrective is. applied to thebelt when riding slightly outof centre; a second stage action in :WhiCh a major corrective, almostpositive in its effect, is applied to the belt side.

Another object is to effect. a first-stage beltcorrecting action byadding a light but definite frictional drag to the belt at one side, bymeans .ofla normally inactive contact roller and, if necessary, toeffect a second-stage. belt-correcting actionby applying a grip to thebelt side by means of the contact roller, in which event the belt tugsthe unit to swivel on its mounting.

The desired belt-centering function of the contact rollers canbe got byplacing them to act on the belt in aplane that is perpendicular to thebelt and contains the idler-roller axis or axes. same relationship tothe belt inboth directions of running. g M

Training idler units as above described are located at intervals inthelength of the conveyor, the other. idlerdsetsbeing as usual of fixedconstruction and requiring no adjustment for reversal of the conveyor.

An example of training units accordingto the invention, as applied to aconveyor of thetype A contact device so placed exercises the statedywillnow be described with reference to the.

accompanying drawings,;in which:

Fig. 1 isvan elevation of an upper belt-troughing unit and aulowerreturmrun unit,v and Fig. 2 is a side'elevationofthe units. Fig.3 is,aplan of IVIV of Fig. 3, being drawn to a larger scale. Fig. 5 is aplan of a lower component of the base of either unit, on which base theidler brackets are mounted; and Fig. 6 is a section on the line VI-VI ofFig. 5 but showing upper and lower components of the base.

With reference firstly to the upper belt-troughing unit, this includesthree belt-troughing idler rollers I, 8 and 9, which are journalled onbrackets II) secured to an upper base plate II which is swivehmounted ona lower base plate I2 secured to the conveyor frame structure I3 (Fig.1.) Each idler roller is borne by ball-bearings, one set of suchbearings being shown at IDA in Fig. 4. The swivel-mounting is such thatthe rollers I to 9 and the base plate I I are free to swivel as a unitto a small extent about a vertical axis at the centre line of theconveyor. The swivel-mounting comprises a ball bearing I4 interposedbetween the two components II and I2 of the base. At each end of theupper base plate II a bracket I5 extends upwards past the outer end ofthe adjacent side roller I or 9 andcarries the contact device.

In the example, the contact device comprises a .small outside roller I6which is in transverse alignment with the rollers I, 8 and 9, and whoseaxis is slightly inclined to the axis of the adjacent roller 1 or 9, andwhich extends inwards from the bracket I5 towards the outer end of theinclined roller. The contact roller I6 comprises a first part ISA, whichis of the same size as each roller 1 and 9 and the inner end of whichnearly touches the outer end of the adjacent side roller, and anenlarged flange-like second part I6B located at the outer end of thefirst part and of larger diameter. The inner face of this second parthas a number of rounded projections IT on it. Each contact roller I6 isborne by a hollow journal I welded to the bracket I5, the arrangementbeing such that the diametral size of the relatively sliding surfaces ofthe roller I6 and journal IE0 is as large as practicable in proportionto the diametral size of the roller portion I6A, so that said surfacesimpose on the roller a frictional drag which renders the rollernoticeably resistant to rotation in comparison with the inclined idlerrollers I and 9 on their antifrictional ballbearings.

In use of the unit, if the belt I8 runs to one side it rides on to theslightly upwardly inclined part [6A of the contact roller. Ordinarily,the

frictional resistance to rotation offered by the roller I6 should. besufilcient to induce the unit thel -upper unit. Fig. 14. is asection on.the line to swivel on the lower base plate I2 into a beltcage-ring 24.tional 'function of preventing dirt from passing, into the ball bearing14. When lubricant is forced into the bearing, some of it squeeezsoutwardsbetween the ring 23 and the base components-Lil i} The extent towhich the upper belt-troughing unit can swivel is limited bypins'lawhich extend into slots, one of which is shown in Fig. 5, beingdenoted by 20. The upper plate ll is maintained central in relation tothe lower platel2--byythe body of a central pin 2| screwed into theupper plate ll. Lubricant is supplied by condliifiS'QZ' to the race ofthe ball bearing [4. A lubricantretaining ring 23 is interposed betweenthe plia-t'esg 29 and 3B is similar to that of the plates H and I 2 ofthe upper units and the means provided for lubrication and sealing arealso similar.

In the event that the return run [8A of the 5 conveyor should becomedisplaced towards one side, it at first contacts the top surface of thecontactor roller 26 at, that side, the frictional drag of thecontactedQriollers tending to swivel the rollers 25 and 26 and the plate29 as a unit 1 "on the stationary base plate 30 and thus to impart acentralising action to the return run IBA. If the belt continues tobecome displaced further sidewise, it; eventually engages the enlargedflangelike outer part of the roller 26, said part 15 acting as a limitstop to the sidewise motion of I l and I2, said ring closely surroundingthe usual The ring 23 performs the-addithe belt and ensuring that therequisite swivelling motion of the unit 25, 26, 29 takes place.

It will be manifest that the surfaces of the rollers 26 contacted by thebelt lie at points in atransverse plane Q -Q which containsthe axis ,ofthe v.roller 25 and .which is perpendicular to thelower run [8A of thebelt. Thus, the belt central-i'sing action takes place irrespectively'ofand I2, thus forming a seal and also carrying 2 away from the proximityof the ring 23 anydirt which might have reached there.

- As will be seen best in Figs. l8 (not shown in Fig. 3) should bedisplaced side- 'wise from its central setting, the contact rollers 2and 3, if the belt will act on the belt at points along a transverse"plane which is indicated by the line P-P in Fig. 2 and of which theright-hand portion is represented by the section-line IV-IV in Fig. 3,said ,:plane beingperpendicular to the belt and the ;'H,XBS of the idlerrollers I, 8 and 9 being con- .tained in said plane. It is by virtue ofthis arrangement that the-contact rollers exercise their .centralisingfunction irrespectively of the direc- .;tion in which the belt istravelling forthetime being. v

1 Modifications may be madewithout departing from the scope of theinvention. For instance, instead of having contact rollers slightlyinclined .to the inclined troughing rollers I and 9, each ,contactroller may be coaxial with the adjacent .troughing roller and may haveits inner portion [6A made with a slight outwardly divergent taper. 1"In the foregoing description with reference to the drawings, theinvention has been described ,only as applied to the upper unit whichcomprises -.the troughing idler rollers 'l, 8 and 9 that support theconveying run of the belt I8.- The in- ;vention is also applicable tounits having rollers which support a flat conveyor, typical units of thikind'being used in the conveyor herein described by way of example asapplied to the lower return run of the belt I8. A lower unit is shown inFigs. 1 and 2.

Referring to Figs.,1 and 2, the lower run of :the conveyor is denoted byIBA. As shown, the .lower unit comprises a single horizontal idlerroller 25 which supports the lower run I8A, maintaining the belt in flatform. The roller 25 is associated at opposite ends with contactorrollers .26 each of which has the same construction as, and is mountedon large-surface bearings similarly to, each of the contactor rollers isof the .upper units. The contact rollers 26 are arranged coaxial to thebelt-supporting roller 25, the axle .21 of which is journalledinbrackets 23 on the upper plate29 of a base including also a lower plate3ll secured to the stationary side structure "3Lof the conveyor.

The construction and arrangement of the upper and lower ba e 19 68 thedirection in whichthe belt .is .travelling for the time being. 1 ,Itwill be manifest that the invention provides a self-aligningendless-belt idler unit comprising one or more anti-friction rollers 25or I, 8, and 9 and supported by an anti-friction swivel mounting. 29, 3Bor ll, 12, with beltcorrecting end ,rollerassemblies each-comprising abearing IBC, acontact roller i6 journalled on said bearing in slidingfrictional engagement therewith, the contact' rollerjfi being arrangedbeyond an end of ,the unit so that in normal central running of the,endless beltthe contact roller is stationary, being clear-of the belt18, a roller surface IBA on the contactrollerwhichsurface is contactedby the underside. of. the belt 18 only if the belt rides sidewise,.and.whichinclines upwards relative to the unders-ideof the belt so as to beall the better .engaged thereby,.and an outer enlargement IBB on thecontact rollen-havingrounded projections I! to'engage the upperside ofthebelt if thebelt rides excessively sidewise, 1 0vv that the belt isgripped between said surface and projections and in effect imparts asuccession of corrective tugs tothe unitafThat is to say, whenever thebelt is fully displaced sidewise, its side is gripped between thesurface. ISA of the now rotating contact roller 16 and that projectionI! which; for the time being, is passing through the topmost position inwhich aprojection I1 is shown in Fig.5. In the continued. rotation ofthe contact roller i6,..the active" projection Has it follows itscircular path must press deeper into the nearly straight belt side.Thus, because of the action of the .projection H, the belt will tug theentire unit .to swivel about its axis (pin 2|).

,Iclaim:

1. In a self-aligning endless-belt idler unit which in use issupportedby a swivel mounting, "a belt-correcting end roller assemblycomprising a bearing supported on said unit, a contact roller journalledonsa'id bearing in frictionalen ag'ement the'rewithQsaid contact rollerbeing arrangedbeyond an end of said unit so that in normal centralrunning of the endless belt'the contact roller rests stationary beyondthe belt, a roller surface on said contact roller which surface iscontacted by the underside of the belt only ifthe belt rides sidewise,and an outer enlargement on said contact roller, having projectbelt isgripped between said surface and projecting means.

2. In a self-aligning endless-belt idler unit which comprises a supportand several antifriction rollers arranged thereon to form a conveyorbelt into trough formation and which in use is supported by ananti-friction swivel mounting, said rollers including two outer rollerseach set at an inclination, a belt-correcting end roller assembly ateach end of said unit, each assembly comprising a bearing which ismounted on said support and the axis of which is in the same transverseplane as the axes of said outer rollers, a contact roller journalled onsaid bearing in sliding frictional engagement therewith, said contactroller being arranged beyond an adjacent one of said outer rollers sothat in normal central running of the trough-formed belt the contactroller rests stationary beyond the belt, a roller surface on saidcontact roller which surface is contacted by the underside of the beltonly if the belt rides sidewise and which inclines upwards relative tothe active surface of said adjacent outer roller and an outerenlargement on said contact roller having rounded projections to engagethe upperside of the belt if the belt rides excessively sidewise, sothat the belt is gripped between said roller surface and projections.

3. In a self-aligning endless-belt idler unit which comprises a supportand several rollers arranged thereon to form a conveyor belt into troughformation and which in use is supported by a swivel mounting, saidrollers including two outer rollers each set at an inclination, abeltcorrecting end roller assembly at each end of said unit, eachasembly comprising a bearing which is mounted on said support and theaxis of which is in the same transverse plane as the axes of said outerrollers, a contact roller journailed on said bearing in frictionalengagement therewith, said contact roller being arranged beyond anadjacent one of said outer rollers so that in normal central running ofthe troughformed belt the contact roller rests stationary beyond thebelt, a roller surface on said contact roller which surface is contactedby the underside of the belt only if the belt rides sidewise, and anouter enlargement on said contact roller having projecting means toengage the upperside of the belt if the belt rides excessively sidewise,so that the belt is gripped between said roller surface and projectingmeans.

4. In a self-aligning endless-belt idler unit which comprises a supportand an anti-friction idler roller thereon and which in use is supportedby an anti-friction swivel mounting, a belt-correcting end rollerassembly at each end of said unit, each assembly comprising a bearingwhich is mounted on said support and the axis of which is in the sametransverse plane as the axis of said idler roller, a contact rollerjournalled on said bearing in sliding frictional engagement therewith,said contact roller being arranged beyond an end of said idler roller sothat in normal central running of the endless belt the contact rollerrests stationary beyond the belt, a roller surface on said contactroller which surface is contacted by the underside of the belt only ifthe belt rides sidewise and which inclines upwards relative to theactive surface of said idler roller, and an outer enlargement on saidcontact roller having rounded projections to engage the upper side ofthe belt if the belt rides excessively sidewise, so that the belt isgripped between said roller surface and projections.

5. In a self-aligning endless-belt idler unit which comprises a supportand an idler roller thereon and which in use is supported by a swivelmounting, a belt-correcting end roller assembly at each end of saidunit, each assembly comprising a bearing which is mounted on saidsupport and the axis of which is in the same transverse plane as theaxis of said idler roller, a contact roller journalled on said bearingin frictional engagement therewith, said contact roller being arrangedbeyond an end of said idler roller so that in normal central running ofthe endless belt the contact roller rests stationary beyond the belt, aroller surface on said contact roller which surface is contacted by theunderside of the belt only if the belt rides sidewise, and an outerenlargement on said contact roller having projecting means to engage theupperside of the belt if the belt rides excessively sidewise, so thatthe belt is gripped between said roller surface and projecting means.

6. In a self-aligning endless-belt idler unit, including ananti-friction roller and a support by which the roller is carried andwhich in use is supported by an anti-friction swivel mounting, abelt-correcting end roller assembly comprising a bearing mounted on saidsupport and arranged beyond an end of said anti-friction roller, acontact roller journalled on said bearing in sliding frictionalengagement therewith so that in. normal central running of the endlessbelt the: contact roller rests stationary beyond the belt, a rollersurface on said contact roller which surface is contacted by theunderside of the belt only if the belt rides sidewise and which inclinesupwards relative to said underside, and an outer enlargement on saidcontact roller having rounded projections to engage the upperside of thebelt if the belt rides excessively sidewise so that the belt is grippedbetween said roller surface and projections.

JAMES THOMSON.

REFERENCES CITED The following references are ofrecord in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,572,555 Nelson Feb. 9, 19261,705,558 Cuddihy Mar, 19, 1929 2,012,089 Sayers Aug. 20, 1935 2,109,923Lemmon Mar. 1, 1933

